Véronique-Isabelle Forest

The relationship between upper airway collapse and the severity of obstructive sleep apnea syndrome: a chart review

BackgroundWe sought to determine the ability of the endoscopic Mueller maneuver (MM) to predict the severity of OSAS based on upper airway (UA) collapse.MethodsThis chart review retrospectively analyzed the results of endoscopic Mueller maneuvers examining the UA on 506 patients suspected of having OSAS. There were 3 areas of UA collapse that were evaluated: velopharynx (VP), base of tongue (BOT), and lateral pharyngeal walls (LPW). A sleep study was done after the examination to assess the severity of OSAS based on the apnea-hypopnea index (AHI).ResultsA total of 506 patients met criteria for OSAS, with 194 mild cases (5u2009≤u2009AHIu2009<u200915), 163 moderate cases (15u2009≤u2009AHIu2009<u200930) and 149 severe cases (30u2009≤u2009AHI). At the VP, 30 patients had minimal collapse (mean AHIu2009=u200917); 41 patients had moderate VP collapse (mean AHIu2009=u200925); 392 patients had severe VP collapse (mean AHIu2009=u200927). At the BOT, 144 patients had minimal collapse (mean AHIu2009=u200919); 187 patients had moderate BOT collapse (mean AHIu2009=u200924); 175 patients had severe BOT collapse (mean AHIu2009=u200933). At the LPW, 158 patients had minimal collapse (mean AHIu2009=u200920); 109 patients had moderate LPW collapse (mean AHIu2009=u200925); 120 patients had severe LPW collapse (mean AHI =33). The correlations found between VP collapse, BOT collapse, and LPW collapse and OSAS severity were: ru2009=u20090.069 (95xa0% CI; −0.022, 0.16), ru2009=u20090.26 (95xa0% CI; 0.18, 0.34) and ru2009=u20090.22 (95xa0% CI; 0.12, 0.31), respectively.ConclusionsIn this study, the degree of collapse of the UA at all levels, especially at the BOT and LPW levels, correlate significantly with the severity of OSAS. The Mueller maneuver helped identify patients with severe sleep apnea based on UA collapse. The MM cannot be used to diagnose OSAS, but can be a valuable tool to help the physician estimate the severity of sleep apnea and the urgency to obtain a sleep study.

Frozen section analysis and sentinel lymph node biopsy in well differentiated thyroid cancer

BackgroundThe aim of this study is to prospectively review the role of sentinel lymph node (SLN) biopsy in the management of well differentiated thyroid carcinoma (WDTC), and to determine the efficacy of intraoperative frozen section analysis at detecting SLN metastasis and central compartment involvement.MethodsThe SLN biopsy protocol using 1% methylene blue was performed in 300 patients undergoing thyroidectomy for WDTC. A limited pretracheal central compartment neck dissection (CCND) was performed on all patients. Lymph nodes staining blue were considered as SLN’s. Both frozen and permanent section analyses were performed.ResultsSLN’s with metastasis were found in 14.3% (43/300) of cases. Of this, 11% (33/300) were positive on intraoperative frozen section analysis. Frozen section results failed in predicting central compartment involvement in 15 cases (5%) whereas central neck compartment involvement was missed in 5 cases (1.7%) when based on permanent section results. On frozen section analysis, the sensitivity, specificity, positive predictive value and negative predictive value (95% CI) of our SLN biopsy technique aiming to remove all disease from the central compartment was 68.8% (53.6-80.9), 100% (98.1-100), 100% (87.0-100) and 94.4% (90.7-96.7) respectively with Pu2009<u20090.0001. On permanent section analysis, the values were 89.6% (76.6-96.1), 100% (98.1-100), 100% (89.8-100), and 98.1% (95.3-99.3) with Pu2009<u20090.0001.ConclusionThis data series demonstrates that patients with WDTC have positive SLN’s in 14.3% of cases. Moreover, when the SLN’s are negative for metastasis on frozen section, the central compartment was disease-free in 94.4% of cases. Finally, this study shows that 23.3% of positive SLN’s were false negatives on intraoperative frozen section. According to this data, SLN involvement is an accurate predictor of central compartment metastasis, however surgeons should use caution when relying on intraoperative frozen section to determine whether to perform a CCND.

Completion thyroidectomy: predicting bilateral disease

IntroductionIt is not uncommon for patients with indeterminate thyroid nodules to undergo diagnostic hemithyroidectomy. When the final pathology determines that the nodule is in fact malignant, patients require counseling as to the whether a completion thyroidectomy is necessary.Objectives1.Determine the incidence of well differentiated thyroid cancer (WDTC) in the contralateral thyroid lobe in patients undergoing completion thyroidectomy.2.Identify features of the malignant tumor in the initial resection that increase the likelihood of malignancy in the contralateral lobe.MethodsRetrospective chart review of 97 patients who underwent hemithyroidectomy and completion thyroidectomy in a university’s teaching hospital network between 2006 and 2012. Pathology reports from both surgeries as well as patient and thyroid nodule characteristics were reviewed.ResultsOf the 97 patients, 47 (48xa0%) had a malignancy in the contralateral lobe. In the contralateral lobe, 42/47 (89xa0%) of malignancies were papillary microcarcinomas (PMC) and 15/42 (36xa0%) of the PMC were multifocal. Multifocal malignancies in the initial specimen had a 60xa0% rate of contralateral malignancy and were found to be a predictor of bilateral disease (pu2009=u20090.04) with ORu2009=u20092.74 (95xa0% CI: 1.11–6.79; pu2009=u20090.003) in WDTC and ORu2009=u20093.59 (95xa0% CI:1.35 9.48; pu2009=u20090.01) in papillary cancer specifically. There was no statistical significant correlation established for the following variables: presence of positive cervical nodes, extrathyroidal extension, positive resection margins, size and angio-lymphatic invasion. Moreover, there was no statistical correlation between any of the variants of papillary thyroid cancer and bilateral disease, even though most aggressive subtypes were found to be bilateral.ConclusionIn this study, the rate of malignancy in the contralateral lobe was 48xa0%. Multifocality and presence of an aggressive subtype of papillary thyroid cancer in the initial specimen were found to be more important variables to consider in decision-making regarding completion thyroidectomy than size of the initial tumor alone.

The Mcgill thyroid nodule score - does it help with indeterminate thyroid nodules?

BackgroundUltrasound guided fine-needle aspiration (USFNA) biopsy of thyroid nodules often gives a result of indeterminate pathology, placing thyroid specialists in difficult management situations. The aim of this study is to evaluate the incidence of malignancy in patients undergoing surgery and to correlate these results with the McGill Thyroid Nodule Score (MTNS).MethodsWe performed a retrospective study comparing USFNA results, MTNS and histopathology of patients undergoing thyroid surgery between 2010 and 2012. Pre-operative USFNA results were divided into three subgroups: benign, indeterminate and suspicious for/malignant. The indeterminate USFNA subgroup comprised of Bethesda type III (atypia of undetermined significance) and Bethesda type IV (follicular neoplasms, including Hurthle cell neoplasms) lesions. Post-operative histopathology was divided into benign or malignant groups.ResultsOf the 437 patient charts reviewed, 57.0% had an indeterminate USFNA biopsy. Within the indeterminate group, the malignancy rate was 39.8%. For indeterminate USFNA, the median MTNS was 7 (32% risk of malignancy) for benign nodules and 9 (63% risk of malignancy) for malignant nodules on post-operative histopathology (pu2009<u20090.05).ConclusionThe rate of malignancy in operated patients with an indeterminate USFNA result was 39.8%. The MTNS can be of value to thyroid specialists in pre-operative decision-making when dealing with an indeterminate result of a thyroid nodule on USFNA.

The McGill Thyroid Nodule Score’s (MTNS+) role in the investigation of thyroid nodules with benign ultrasound guided fine needle aspiration biopsies: a retrospective review

BackgroundUltrasound guided fine needle aspiration (USFNA) biopsies of thyroid nodules sometimes create a decision-making dilemma for surgeons as they may yield falsely benign results. The McGill Thyroid Nodule Scoreu2009+u2009(MTNS+) was developed to aid in clinical guidance regarding the management of patients with these USFNA results. The aim of this study was to assess the MTNS+ as a clinical tool in patients with benign preoperative thyroid nodule USFNAs and to analyze the relationship between nodule size and malignancy in these patients.MethodsWe conducted a retrospective chart review of 1312 patients who underwent thyroidectomies between 2010 and 2015 at the McGill University Teaching Hospitals. Patients with Bethesda II (benign) USFNA results, calculated MTNS+, and nodule size evaluated on ultrasound were included in the study. The false-negative rate was calculated, and MTNS+ and nodule size were each compared to final pathology results. Binary logistic regression was used for statistical analysis.ResultsOf the 1312 patients, 101 met the inclusion criteria and together had an average MTNS+ score of 6.83, which corresponds to a predicted malignancy rate between 25 and 33xa0%. Final pathology revealed malignancy in 16 (15.8xa0%) subjects. The average MTNS+ of patients with malignant nodules on surgical pathology was 8.25, while that of patients with benign nodules was 6.56.Patients with nodule size 1–1.9xa0cm (a) and 2–2.9xa0cm (b) each had an equal rate of malignancy of 2.97xa0% (nu2009=u20093), nodule size 3–3.9xa0cm (c) had a rate of 1.98xa0% (nu2009=u20092), and nodule size ≥4xa0cm (d) a rate of 7.92xa0% (nu2009=u20098).ConclusionThe rate of malignancy (15.8xa0%) is higher than expected when reviewing the risk of malignancy in nodules considered as Bethesda class 2. On the other hand, the rate is lower than the 25–33xa0% predicted by the MTNS+. We also found a higher malignancy rate for nodules above 4xa0cm in size, but size was a poor predictor of malignancy when used alone. Therefore, while the MTNS+ may be helpful at helping to identify USFNAs that are incorrectly classified as benign, the percentage risk of malignancy is lower than expected.

The role of repeat fine needle aspiration in the management of indeterminate thyroid nodules

BackgroundManagement decisions are not straightforward when the Ultrasound Guided Fine Needle Aspiration (USFNA) demonstrates a Bethesda score of either category III or IV, and a diagnostic hemi-thyroidectomy or a repeat USFNA (r-USFNA) could be performed. The aim of this study is to assess the effectiveness of r-USFNA in the management of indeterminate thyroid nodules by evaluating the likelihood of obtaining a definite diagnosis.MethodsWe reviewed the medical records of all patients with thyroid nodules between 2011 and 2015 at the Jewish General Hospital (Montreal, Canada). Three hundred fifty-one patients who had undergone a surgical procedure (hemi or total thyroidectomy) and a diagnosis of B3 or B4 on the primary USFNA (p-USFNA) were included in the study. Ninety-six of the included patients also had a repeat USFNA prior to the surgery. Demographic data, type of procedure, and McGill Thyroid Nodule Score (MTNS) were obtained from the medical records. Malignancy rates were calculated based on the final surgical histopathology report.ResultsUpon r-USFNA, an average 76xa0% of patients did not change Bethesda categories, 7.4xa0% downgraded to a benign category. The results showed that, on an average 17.3xa0% of patients with p-USFNA of B3 and 20xa0% of patients with p-USFNA of B4, upgraded to a malignant or suspicious for malignancy category, thus changing the clinical management to total thyroidectomy. Our data demonstrates that r-USFNA facilitates choosing the correct surgery of total thyroidectomy in about 20xa0% of nodules that have upgraded from B3/B4 to a more definite malignant category.Conclusionsr-USFNA in patients with indeterminate diagnoses (B3 or B4) increases categorization into more definite categories. Approximately 20xa0% of patients are found to have malignant thyroid nodules and suspicious for malignancy thyroid nodules upon repeating the biopsy, hence a diagnostic hemi-thyroidectomy was avoided and a more definitive surgery could be performed. Furthermore, repeat USFNA results in a fewer number of hemi-thyroidectomy and completion thyroidectomy procedures.

Ultrasound-guided fine-needle aspiration of thyroid nodules: Does size matter?

PURPOSEnSome authors have questioned the benefit of fine-needle aspiration (FNA) of thyroid nodules ≥ 4 cm. They report that the results of the FNA are not as reliable when compared to nodules <4 cm. The aims of this study are to evaluate the accuracy and predictive values of ultrasound-guided FNA (USFNA) of thyroid nodules ≥ 4 cm and compare these findings to nodules <4 cm.nnnMETHODSnA retrospective study of 998 patients who underwent thyroid surgery between 2006 and 2012 at the McGill University Thyroid Cancer Center was performed. USFNA and post-operative pathology diagnoses of nodules ≥ 4 cm versus those <4 cm were compared. Pre-operative USFNA results were divided into three groups: benign, indeterminate, and malignant/suspicious for malignancy subgroups. Post-operative results were separated into benign and malignant groups.nnnRESULTSnThere were 225 patients with nodules ≥ 4 cm and 773 patients with nodules <4 cm. The sensitivity, specificity, positive predictive value and negative predictive value for USFNA of nodules ≥ 4 cm were 84.62% (CI 71.91-93.10), 91.49% (CI 79.6-97.58), 91.67% (CI 80.0-97.63) and 84.31% (CI 71.4-92.95), respectively. The sensitivity, specificity, positive predictive value and negative predictive value for USFNA of nodules <4 cm were 90.48% (CI 86.1-93.8), 85.92% (CI 75.6-93.02), 95.8% (CI 92.41-97.96) and 71.76% (CI 60.95-81.0), respectively. The difference in diagnostic accuracy of USFNA between both groups was not statistically significant (p>0.05).nnnCONCLUSIONnThis study shows that the sensitivity, specificity, positive predictive value and negative predictive value for USFNA of nodules ≥ 4 cm are similar to that of smaller nodules. It is therefore suggested that these nodules undergo USFNA.

The first Canadian experience with the Afirma® gene expression classifier test

BackgroundThyroid nodules are common and often benign, although prove to be malignant upon surgical pathology in 5–15% of cases. When assessed with ultrasound-guided fine-needle aspiration (USFNA), 15–30% of the nodules yield an indeterminate result. The Afirma® gene expression classifier (AGEC) was developed to improve management of indeterminate thyroid nodules (ITNs) by classifying them as “benign” or “suspicious.” Objectives were (1) to assess the performance of the AGEC in two Canadian academic medical centres (2), to search for inter-institutional variation and (3) to compare AGEC performance in Canadian versus American institutions.MethodsWe undertook a retrospective cohort study of patients with indeterminate cytopathology (Bethesda Class III or IV) as per USFNA who underwent AGEC testing. We reviewed patient demographics, cytopathological results, AGEC data and, if the patient underwent surgery, results from their final pathology.ResultsIn total, we included 172 patients with Bethesda Class III or IV thyroid nodules underwent AGEC testing, 109 in Montreal, Quebec and 63 in St. John’s, Newfoundland, in this study. Among the nodules sent for testing, 55% (60/109) in Montreal and 46% (29/63) in St. John’s returned as “benign.” None of these patients underwent surgery. On the other hand, 45% (49/109) nodules in Montreal and 54% (34/63) in St. John’s were found to be “suspicious,” for a total of 83 specimens. Seventy seven of these patients underwent surgery. Both in Montreal and St. John’s, the final pathology yielded malignant thyroid disease in approximately 50% of the specimens categorized as “suspicious.” Since 2013, no patient diagnosed with a benign nodule as per AGEC testing was found to harbor a malignant thyroid nodule on follow-up.ConclusionsMolecular analysis is increasingly used in the management of indeterminate thyroid nodules. This study highlights the experience of two Canadian centres with AGEC testing. We found inter-institutional variability in the rate of nodules returning as “benign,” however we found similar rates of confirmed malignancy in nodules returning as “suspicious.” According the literature, results for AGEC testing in two Canadian institutions align with results reported in American centres.

Seasonal Difference in Postthyroidectomy Hypocalcemia: A Montreal-Based Study

Objective Hypocalcemia following thyroidectomy often prolongs hospital stay and is potentially life-threatening. The objective of this study is to determine whether the season when thyroidectomy is performed is associated with postoperative hypocalcemia. Study Design Retrospective case series of patients undergoing thyroid surgery from 2009 to 2015. Setting Tertiary care academic institution in Montreal, Canada. Subjects and Methods A consecutive sample of 823 patients undergoing thyroidectomy by a single high-volume otolaryngologist for a suspected or confirmed thyroid malignancy. Patient demographics, procedure type, calcium and vitamin D supplementation, and seasonal rate of hypocalcemia postthyroidectomy were calculated and compared. Results Average seasonal rates of postthyroidectomy hypocalcemia in the winter, spring, summer, and autumn were, respectively, 8.3% (8 of 216), 7.3% (12 of 165), 1.5% (3 of 201), and 3.5% (8 of 228; P < .005). Patients operated in the winter were 5.6 times more likely to develop hypocalcemia as compared with those in the summer (P < .01; 95% confidence interval: 1.7-18.7). In a multiple regression analysis factoring in season when surgery was performed, procedure type, and preoperative vitamin D/calcium supplementation, surgery occurring in the winter predicted a hypocalcemia event (correlation coefficient [SE]: 0.72 [0.024], P = .026; 0.006 [0.025], P = .81; 0.004 [0.019], P = .82, respectively). Conclusion In this study, patients undergoing thyroidectomy in the winter months were more likely to develop postoperative hypocalcemia when compared with those operated in the summer. Further studies are needed to understand the role of vitamin D in the observed seasonal difference in hypocalcemia rates.

Preoperative vocal cord paralysis and its association with malignant thyroid disease and other pathological features

BackgroundVocal cord paralysis (VCP) is found in both benign and malignant thyroid disease. This study was performed to determine if the presence of preoperative VCP predicts malignancy.MethodsA retrospective analysis was performed on a cohort of 1923 consecutive patients undergoing thyroid surgery. The incidence of preoperative VCP was recorded. Patient and nodule characteristics were correlated with final pathology.Results1.3xa0% of our cohort was found to have preoperative VCP. Malignant pathology was discovered in 76xa0% of patients with preoperative VCP. Among these patients, 72xa0% had a left sided paralysis. 10.5xa0% of patients with preoperative VCP had perineural invasion (PNI) on final pathology, compared to 1.1xa0% of patients with normal VC function.ConclusionPreoperative VCP appears to be a strong, though not an absolute, indicator of malignancy. Most VCP were on the left side. Assessing for preoperative VCP is crucial in all patients who need thyroid surgery, as even benign nodules can be accompanied by preoperative vocal cord paralysis.